Method for drying liquids.



E. M. JOHNSON & E. I. COLLINGS. METHOD FOR DRYING LIQUI'DS. APPLICATIONFILED MAn.s.1915.

1,200,1 1,6. Patented Oct. 3,1916.

lll/lll WIT/VESSES:

A TTOR/VEV in solution' over the heated surface.

UNrrED s'rA'rEs raran'r onirica.

EDWARD 'MEAD JOHNSON AND ERNEST, J. COLLINGS, 4Oil? JERSEY CITY, 'NEWJERSEY,

ASSIGNORS T0 MEAD JOHNSON 6c RATION OF NEW JERSEY'.

CO., OF JERSEY CITY, NEW 'll'lllItSlElY,I A. CORPO- Meri-ion ron. nnYiNGLiauins.

Specicaton of Letters Patent.

Patented Oct. 3, 1916.

l Application led March 8, 1915. Serial No. 12,858.

Liquids, of which the following is a specification.

This invention relates to methods for drying liquids wherein the liquidis dried while thinly spreadl upon a surface, and .isapplicable to allliquids, particularly those containing a solid matter in suspension orsolution. I

lAn object of the invention is to dry highly adhesivesolutions-especially those which are extremely adhesive when heated-bythis method.

A further object of the invention is to dry mix-tures composed ofsolutions of dierent 4degrees of adhesiveness and toregulate theproportions of the diierent solutions so as to obtain the desiredconstitution of the dried product. 0

Our new process of drying consists fundamentally in spreading a film ofa. comparatively low adhesiveness over lthe surface upon place andapplying upon this film a lm of the more adhesive solution to be dried.

An important application of. the process is the drying of syrups. Maltsugar syrup, for example, consists principally of two substances,dextrin and maltose in solution. The maltose is extremely adhesive whenheated, while the'dextrin is much less so. In former processes 'it hasbeen customary to dry the malt sugar syrup by spreading a film of themixture of dextrin and malltplse v is results in bringing a part of theheated mal-V tose in contact with the heatedfsurface and its extremeadhesiveness makes it ydiicult to remove from the heated surface afterdry.- ing.' It is practically impossible to. remove the dried film whenthe ratio of the maltose to the deXtrin in the solution is greater than:45. t According to our new process, 'a solution containing either pureydextrin orv a. high percentage of dextrin and a solution containing ahigh percentage of maltose are spread upon the heated surface separatelyand successively, A. ilm of the high 4dexsolution of.

which the drying is to taketrinsolution is irst applied and over this afilm of the high maltose solution. The film high in dextrin prevents themaltose from coming in contact with the heated surface and inconsequence the two films may easily be scraped of when dried. f

In order that our invention may be clearly understood, we shall proceedto describe the particular adaptation of it which is illus-` trated inthe accompanying drawing. It should 'be clearly understood, however,that our invention is` by no means limited to the particular embodimentillustrated and described.

In theaccompanying drawing, Figure 1` is a cross-sectional elevation ofa device em bodying our invention. Fig. 2 is a fragmentary section of amodified form of the device. y

In the form illustrated the drying apparatus is, inclosed in anair-tight casing l, to which is connected aneXhaust pipe' 13. This makesit possible to conduct the drying in a vacuum. The use of a vacuum is,however, not essential to our invention-and whether or not it is to beused in connection with our invention may be determined by practicalconsiderations as to the cost and rapidity of drying required andparticularly by the nature of the solution to be dried.-

rIhe drying roller 2 is supported upon a 'horizontal axle, oneend ofwhich is hollow to permit the introduction of steam into the interior ofthe roller; Any convenient form of mechanisimnot shown, is provided vtorotate the roller in an anti-clockwise direction.

Thismechanism is such that the speed of rotation may be varied. Belowthe roller 2 are the rollers 3 and 4.. These rollers are supported uponhorizontal axles and are preferably capable of being steam heated likeroller 2. A very small clearance is allowed between these-rollers androller 2, that between roller 3 and roller 2 being equal to thethickness of the film of the liquid to be dried,and thatbetween roller'4 and roller 2 being equal to thethiclmess of two films of solution.Rollers 3 and 4 are provided with mechanism (not shown by which they canbe rotated in' the cloc wise direction., ortions of the' roll'` l`Surrounding the lower ers Band a arethetroug s 5 and 6, in whichare'placed the solutions tobe dried, Inlet pipes 7 and 8 are providedto' admitv the solutions to the troughs .and 6, respectively. are alsoprovided with outlet pipes 9 and 10, which are used when the troughs areWashed out. A .knife 1l is provided to scrape the dried lms from theroller 2. From the knife the dried product The troughs descends into thereceptacle l2.

The operation of the apparatus illustrated in Fig. l is as followsz-Steam is admitted to the roller 2, and preferably to rollers 3 and 4also, to heat them. v The solutions. to be dried are introduced into thetroughs 5 and 6 through pipes 7 and 8, the more adhesive solution beingplaced in trough 6. If, for example, the solution to v be dried is maltsugar-syrup, the solution of n them.

dextrin. or high in dextrin is admitted to trough 5, while the highmaltose solution is run into trough 6. The rollers are then rotated,roller 2 in an anti-clockwise direction and rollers 3 and 4 in aclockwise direction. The peripheral velocity of roller 2 is preferablyslightly greater than that of rollers 3 and 4, so that the l'ihn ofsolution carried up upon rollers 3 and 4 is drawn upon the surface ofroller 2 as it passes over By this arrangement, a film of the solutioncontained in trough 5 is irstapplied to roller 2 and then a iilm of themore adhesive solution in trough 6 is applied outside of this lm. Theilm ol' the more adhesive solution is thus kept out of contact withroller-2 and does not, therefore, *stick to the roller when dried. Thetwo :films are scraped from the roller 2 by the knife ll and fall' intothe receptacle 12 in the form of a dry powder.

linl the modification of the apparatus shown in Fig. 2, rollers v3 and 4are placed at such a distance from the roller 2 'that the film ofsolution upon them is not brought directly in contact with the roller 2.Tn this modification, the rollers 3 and 4 are rotated at a sucientlyhigh velocity to throw the solution upon them against the roller 2 bycentrifugal force.

The axles of the rollers 3 and 4 may be so supported as to be verticallyadjustable. lin this case these rollers may beso adjusted as to operateeither as shown in Fig. l or asin rig. e.

vthe trough 5 to The process may be used to dry a single highly adhesiveliquid whichl could not be dried on a heated roller by the ordinarymethod. in this case the adhesive liquid is placed in the trough 6 andoil or other suitable `liquid of lou7 adhesiveness is placed in theroller 2.

An important use of the process `isto ob tain a dry product which iscomposed cfa mixture Aof the solid constituents 'et soluform a lmwhichshall pre-- vent the adhesiye liquid from adhering to' neonatohesive solution is placed in thetrough 6 and is thusprevented fromcoming in contact with the roller. Furthermore, the process permits ofthe regulation of the proportions oi'' the constituents of thediil'erent solutions which appear in the dried product. This is done by'regulatl g the thickness of the films of the various solutions appliedto the roller 2. Regulation may be accomplished in vvarious ways. Thus,a thicker llm or' one solution may be produced by maintaining thatsolution at a higher level in its trough by admitting the solution tothe trough more rapidly. A thicker iilm oi the solution'may also beapplied by rotating the rollerI which is applying the film more rapidly.This method is peculiarly applicable when the ilm is appliedcentrifugally, `as shown in Fig. 2.

lt is obvious that many modifications may be made in the described meansfor carrying out the process without departing from our invention. Thus,the drying roller may itself dip into a trough containing one ci theliquids, ywhile the other liquid is applied by a roller similar toroller 3. 0r one or both of the `solutions may be applied by suitablespraying vdevices or by means oi any other mechanism for applying iilmsto va roller. Tf it is desired to obtain a mixture yof the solidconstituentsof more than two liquids, additional rollers and troughssimilar to rollers 3 and 4- and troughs 5 and 6 may be used, or a numberof spraying devices or other means for applying iilms may be usedy equalto the number of liquids to be dried. Thus, any number ci liquids may bedried and the solid constituents mixed in any desired proportion.

What we claim is:

l. The method of obtaining the solid constituents of an adhesive liquidin dry form, which consists in 'spreadinga lm of a less adhesive liquidover a suriace, spreading a iilm of the adhesive liquid over this film,drying said films upon said surface, and removing them from saidlsurface.

2. The method of obtaining the solid constituents 'of an Iadhesiveliquidiny dry form, which consists in spreading a hlm of a less adhesive 4liquid over a heated surface, spreading a lm oi theadhesive liquid overthis. lm, drying said lms upon said surface, and removing said ilms fromsaid surface. u

3. The method of obtaining' a mixture of the solid constituents orliquids of different adhesiveness, which consists in applying a iilm ofthe less adhesive liquid to a surface, applying a film of the moreadhesive liquid over said dim, and scraping said iil'ms-trom saidsurface after they have dried thereon. f 4,'Theymethod of'ohtaining amixture of solid constituents ot liquids, which consists 2in'successively' applying mms 'of Sai@ liquids my@ in applying a film ofsuperimthey Asolid constituents of liquids in given pro.

portions, which vconsists in successively applymg films of said. liquidsto a surface, the thickness of the film of each liquid lbeingproportional to the amount of the solid constituents of that liquiddesired in the dry product, and scraping said superimposed films fromsaid surface after they have dried thereon.

6. The method of obtaining la mixture of the solid constituents ofliquids of different adhesiveness, whichconsists in successivelyapplying films of the said liquids to a heated surface, the nethermostfilm being comosed of one of the liquids of comparatively owadhesiveness, and removing said Elms from said surface after they havedried thereon.

7. vThe method of obtaining a mixture of solid constituents of liquids,which consists in applying a film of one of the liquids to a surface,partially drying said film, applying a film of another liquid Iupon saidpartially dried film,

havedried thereon.

8. The method of obtaining a mixture .of solid-constituents of liquids,which consists one of a surface, applying a film of another of theliquids to said first mentioned film, and scraping said superimposedfilms from said surface after they have dried thereon.

9. A continuous method of obtaining 4a mixture of solid constituents ofliquids which consists in applying a film of one of the liquids to amoving surface, applying a film of another of said liquids to saidsurface at a pointA to the rear of the point Where said first mentionedfilm is applied,

4upon said surface, and removmg sald and scraping said super., imposedfilms from 'said surface after'they the liquids to` this layer,

and scraping said superimposed films from said surface after they havedried thereon.

10. The `method of obtaining the solid constituents of a solution ofmaltose in dry form, which consists in spreading a layer of a lessadhesive l substance over a surface,

spreading a film of themaltose solution' over said layer, drying saidfilm, and remov- :ifng said film and' said layer from said surace. l1'1. The method of obtaining the solid constituents of malt sugar syrupin dry form', vwhich consists in spreading a film of a -solution ofdextrin over a surface, spreadin a 'film of a solution of maltose oversai film, drying said films upon said surface, and removing saidsurface. i

12. The method of obtaining the solid constituents of malt sugar syrupin dry form, Which consists in spreading a fi of the syrupin which theratio of dextrin to maltose is greater than :55 over a surface,spreading a film of a syrup in which the ratio of maltose to dextrin isgreater than 55 :45 over said film, drying said lms films from saidsurface. A

l13. The method of obtaining the solid constituents of an adhesiveliquid in, dry form, which consists in `spread1ng a layer of a lessadhesive material over a surface, spreading a film ofthe adhesive liquidover dryingA said film, and removing said film and said layer from saidsurface. In testimony whereof, We have-hereunto set our hands 1n thepresence of Witnessesthis fourth day .of March, 1915.

EDWARD MEAD JOHNSON. ERNEST J. COLLINGS.

`Witnesses to both signatures:

M. J. HILL, FRED-L. ROY.

lms from said

